def solve():
    from collections import defaultdict

    N,P=map(int,input().split())
    A=list(map(int,input().split()))

    A_max=max(A)

    Ans=0; v=1; Q=P
    while Q<=A_max:
        E=defaultdict(int)
        for a in A:
            E[a%Q]+=1

        for y in E.values():
            Ans+=y*(y-1)//2
        v+=1; Q*=P
    return Ans

#==================================================
print(solve())